Remember the days of the old school yard? You may prefer to forget them, but many people are nostalgic for the days of grazed knees, poor food and double geography.

A new malware campaign seen in the last few days plays on the popularity of websites like Classmates.com and FriendsReunited, by posing as an invitation to an imminent school reunion.

Part of the email reads:

" With pride and joy we invite you to share a special day in our lives and join us for the Class Reunion on Friday, January 16th 2009.
Bring the gang from Our High School back together again!
Great party - from start to finish! "

Clicking on the link doesn't of course take you to the real Classmates website, but a bogus site which tries to fool you into installing an update to Adobe Flash to view a video invitation to your school reunion. Of course, the update is really a malicious Trojan horse designed to compromise your computer.

With many people returning to the office after the holiday break there is a danger that some will click on the link without thinking as they plough through their inboxes.

As ever, be wary of unsolicited emails, and if you are going to update software and plugins on your computer make sure you are getting those updates from the real, legitimate producer of the code, not a third party website that a hacker could have set up.